Cover plate and battery

Abstract

The utility model discloses a cover plate and a battery, the cover plate comprises a cover body, the cover body is provided with a first mounting hole and a second mounting hole, and one side, close to the interior of the battery, of the cover body is provided with a groove; a first pole and a second pole; the deformation part is arranged on the side, close to the interior of the battery, of the cover body, when the internal pressure of the battery is smaller than a preset value, the deformation part is separated from the cover body, and when the internal pressure of the battery is increased to the preset value, the other end of the deformation part moves towards the direction of the cover body and then makes contact with the cover body to form a short circuit; and the groove is used for accommodating the other end of the deformation piece. According to the embodiment of the invention, the groove can be used as a stamping accommodating deformation space on the cover body, and the groove and the deformation piece are matched with each other, so that not only is mistaken short circuit avoided, but also the situation that the size of the battery is increased due to the arrangement of the deformation piece can be avoided.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a cover plate and a battery. Background Technology

[0002] With the rapid application of sodium-ion batteries in energy storage and power fields, their safety has become a core bottleneck restricting their development. In existing technologies, layered oxide cathodes are prone to lattice oxygen evolution and thermal runaway under high voltage, while hard carbon anodes suffer from sodium dendrite growth and continuous gas generation due to uneven SEI film at the interface. Furthermore, the synergistic failure of the positive / negative electrode-electrolyte interface further exacerbates the risk of thermal runaway. Although existing patents have improved local stability through single-electrode modification, they have failed to address the cross-contamination and synergistic heat release issues of the entire battery system under extreme conditions. Therefore, a multi-level synergistic protection technology is urgently needed to overcome these safety barriers.

[0003] The existing solution uses a flip plate. When the battery is under extreme conditions, such as excessive internal temperature or excessive internal pressure, the flip plate can flip to short-circuit the positive and negative terminals of the battery, thereby protecting the battery and solving the battery safety problem.

[0004] However, in the existing technology, the flip plate is located in the through hole on the top cover, and an electrical connection plate is set on the outside of the top cover. When the flip plate comes into contact with the electrical connection plate, a short circuit occurs. The above design is likely to result in a large battery size. Utility Model Content

[0005] One objective of this application is to provide a cover plate that can solve the technical problem of large battery size caused by the setting of flip plates in the prior art.

[0006] Another object of this application is to provide a battery including the aforementioned cover.

[0007] To achieve the above objectives, this application provides the following technical solutions.

[0008] A cover plate according to a first aspect embodiment of this application includes: a cover body, the cover body having a first mounting hole and a second mounting hole, the first mounting hole being used to install a first terminal post that is insulated from and connected to the cover body, and the second mounting hole being used to install a second terminal post that is electrically connected to the cover body and has the opposite polarity to the first terminal post; a groove being provided on the side of the cover body near the inside of the battery; a first terminal post and a second terminal post, the first terminal post being installed in the first mounting hole and insulated from the cover body, and the second terminal post being installed in the second mounting hole and electrically connected to the cover body, the second terminal post having the opposite polarity to the first terminal post; a deformable member, the deformable member being disposed on the side of the cover body near the inside of the battery, one end of the deformable member being connected to the first terminal post, when the internal pressure of the battery is less than a preset value, the deformable member being spaced apart from the cover body, and when the internal pressure of the battery increases to the preset value, the other end of the deformable member moving toward the cover body and contacting the cover body to form a short circuit, the groove receiving the other end of the deformable member.

[0009] Optionally, the cover plate further includes a connector located on the side of the cover body near the inside of the battery, the connector having the deformable member disposed thereon, and the connector being used to connect to the first electrode post.

[0010] Optionally, the connector includes: a first connecting piece for connecting to a first pole post; and a second connecting piece connected to the first connecting piece, wherein the deformable element is disposed on the second connecting piece.

[0011] Optionally, the deformable part includes a connecting part, a flipping part, and a protrusion. The protrusion is located in the middle of the flipping part and extends toward the direction of the cover. When the internal pressure of the battery increases to a preset value, the flipping part moves toward a position close to the cover so that the protrusion contacts the cover.

[0012] Optionally, the protrusion is a tapered column structure extending toward the direction of the cover. Along the thickness direction of the cover, the radial dimension of the protrusion gradually increases. The groove is a semi-circular groove. The radial dimension of the groove at the position corresponding to the protrusion decreases as the radial dimension of the protrusion decreases.

[0013] Optionally, the cover plate further includes: an insulating member located on the side of the cover body near the inside of the battery, the insulating member having a first through hole, a second through hole and a third through hole, the first through hole corresponding to the position of the first mounting hole for installing a first terminal post that is insulated from and connected to the cover body, the second through hole corresponding to the position of the second mounting hole for installing a second terminal post that is electrically connected to the cover body and has the opposite polarity to the first terminal post, one end of the deformable member being connected to the first terminal post, and the other end of the deformable member corresponding to the position of the third through hole.

[0014] Optionally, one end of the deformable member is located on the side of the insulating member away from the cover.

[0015] Optionally, the first electrode is a negative electrode, the second electrode is a positive electrode, and the cover, the first electrode, and the deformable part are made of the same material.

[0016] Optionally, the distance between one end of the deformable member and the side of the cover near the inside of the battery is H1, and the depth of the groove is H2, where 1.4mm≤H1+H2≤3.5mm.

[0017] A battery according to a second aspect of this application includes: a housing and a cover plate, the cover plate being any of the cover plates described above, wherein a receiving space is enclosed between the housing and the cover plate; and an electrode assembly located within the receiving space.

[0018] According to the cover plate of this application, the deformable component can be placed inside the battery cell during installation. After deforming under pressure, the component contacts the cover, ensuring the universality and consistency of the positive and negative terminals on the outside of the battery, and without excessively occupying space on the outer surface of the cover, which is beneficial for standardized design during cell assembly. Furthermore, by placing the deformable component inside the battery cell, the exposed terminals on the outside of the cell do not need to be additionally enlarged or lengthened, thus not occupying external space of the cover. Additionally, since the deformable component is placed inside the battery cell and there is no need for through-holes in the cover for assembly, the sealing design is greatly reduced, improving safety and reliability. Moreover, since the deformable component is placed inside the battery cell and the external terminals do not need to be designed to be large, the assembly method between the terminals and the cover is not limited to riveting; injection molding can be used based on low-cost design goals. Furthermore, the groove in this embodiment can serve as a stamping space on the cover to accommodate deformation. By using the groove and the deformable component in cooperation, not only is it beneficial to avoid accidental short circuits, but it also avoids increasing the battery size due to the presence of the deformable component.

[0019] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0021] Figure 1 This is an assembly diagram of the housing and electrode assembly according to one embodiment of this application;

[0022] Figure 2 This is an exploded view of a cover plate according to an embodiment of this application;

[0023] Figure 3 This is an assembly diagram of the top cover, insulating component, and adapter piece according to one embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the assembly structure of the negative electrode post, the first connecting piece, the second connecting piece and the deformable part according to another embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the assembly structure of the first connecting piece, the second connecting piece, and the deformable part according to an embodiment of this application;

[0026] Figure 6 This is an assembly diagram of the first connecting piece and the second connecting piece according to an embodiment of this application;

[0027] Figure 7 This is a structural schematic diagram of the inner side surface of the top cover according to an embodiment of this application;

[0028] Figure 8 This is a cross-sectional view of a cover plate according to an embodiment of this application;

[0029] Figure 9 This is a partially enlarged cross-sectional view of a cover plate according to an embodiment of this application;

[0030] Figure 10 This is a schematic diagram of a battery with internal pressure less than a preset value according to an embodiment of this application;

[0031] Figure 11 This is a schematic diagram showing the internal pressure of a battery reaching a preset value according to an embodiment of this application;

[0032] Figure 12 This is a partial cross-sectional view of a cover plate according to an embodiment of this application;

[0033] Figure 13 yes Figure 12 A magnified view of region A, shown in the middle circle;

[0034] Figure 14 This is a cross-sectional view of the cover according to an embodiment of this application;

[0035] Figure 15 yes Figure 14 A magnified view of region B, shown in the middle circle.

[0036] Attached icon number

[0037] Cover 10; First mounting hole 11; Second mounting hole 12; Groove 13;

[0038] First pole piece 21; Second pole piece 22;

[0039] Insulating component 30; First through hole 31; Second through hole 32; Third through hole 33;

[0040] Deformable part 40; Connecting part 41; Flipping part 42; Protrusion 43;

[0041] First connecting piece 50;

[0042] Second connecting piece 60;

[0043] 71. Plastic on the positive electrode; 72. Plastic on the negative electrode; 73. Sealing ring; 74. Positive electrode connecting block; 75. Positive electrode adapter piece;

[0044] Casing 80;

[0045] Electrode assembly 90. Detailed Implementation

[0046] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0047] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0048] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0049] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0050] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0051] The cover plate according to an embodiment of this application is described in detail below with reference to the accompanying drawings.

[0052] like Figures 1 to 15 As shown, the cover plate according to an embodiment of this application includes: a cover body 10, a first pole post 21, a second pole post 22, and a deformable member 40.

[0053] Specifically, the cover 10 has a first mounting hole 11 and a second mounting hole 12. A groove 13 is provided on the side of the cover 10 closest to the battery interior. A first terminal 21 and a second terminal 22 are also provided. The first terminal 21 is installed in the first mounting hole 11 and is insulated from the cover 10. The second terminal 22 is installed in the second mounting hole 12 and is electrically connected to the cover 10. The polarity of the second terminal 22 is opposite to that of the first terminal 21. A deformable member 40 is located on the side of the cover 10 closest to the battery interior. One end of the deformable member 40 is connected to the first terminal 21 installed in the first mounting hole 11. When the internal pressure of the battery is less than a preset value, the deformable member 40 is separated from the cover 10. When the internal pressure of the battery increases to the preset value, the other end of the deformable member 40 moves towards the cover 10 and contacts the cover 10 to form a short circuit. The groove 13 accommodates the other end of the deformable member 40.

[0054] In other words, the cover plate according to the embodiments of this application can be used for a battery, wherein the battery may include a housing 80 and a cover 10, and a receiving space is enclosed between the housing 80 and the cover 10, and an electrode assembly 90 is installed in the receiving space. The housing 80 has a long side, a wide side, and a thick side, for example, the long side extends along the Z-axis direction, the wide side extends along the X-axis direction, and the thick side extends along the Y-axis direction. When multiple electrode assemblies 90 are installed in the housing 80, the multiple electrode assemblies 90 can be arranged sequentially along the Y-axis direction. The first electrode post 21 and the second electrode post 22 are spaced apart along the Z-axis direction.

[0055] According to the embodiments of this application, the cover plate combines a cover body 10 and a deformable member 40. The cover body 10 can be a metal part, such as a sheet of aluminum. The cover body 10 has a first mounting hole 11 and a second mounting hole 12 as electrode post holes, for example, the first mounting hole 11 and the second mounting hole 12 are spaced apart along the Z-axis direction. A first electrode post 21 is installed in the first mounting hole 11, and a second electrode post 22 is installed in the second mounting hole 12. The first electrode post 21 and the second electrode post 22 have opposite polarities. For example, the first electrode post 21 is a negative electrode post, and the second electrode post 22 is a positive electrode post, extending along the X-axis direction. Moreover, the first electrode post 21 is insulated from the cover body 10, and the second electrode post 22 is electrically connected to the cover body 10. For example, the positive electrode post is electrically connected to the cover body 10, so the cover body 10 is positively charged; the negative electrode post is connected to the cover body 10 through an insulating structure; the deformable member 40 is directly or indirectly connected to the negative electrode post, and the deformable member 40 is negatively charged.

[0056] Furthermore, the inner side of the cover 10 is provided with a groove 13 that is recessed in the direction of its own thickness, for example, the opening of the groove 13 faces downward. When the other end of the deformable member 40 contacts the cover 10 under pressure, the groove 13 can serve to accommodate the other end of the deformable member 40. That is to say, the side of the cover 10 facing the internal electrode assembly 90 of the battery is also provided with a groove 13, which can serve as a receiving groove for the other end of the deformable member 40. When the internal gas pressure of the battery increases, the deformable member 40 will deform, and the other end of the deformable member 40 will move towards the cover 10. The other end of the deformable member 40 will contact the inner wall of the groove 13. By providing the groove 13, the contact area can be increased, and the protrusion 43 can be prevented from occupying the space in the X-axis direction.

[0057] Therefore, according to the cover plate of this application embodiment, the deformable part 40 can be placed inside the battery cell during installation. The deformable part 40, after deforming under pressure, contacts the cover 10, ensuring the universality and consistency of the positive and negative terminals on the outside of the battery, and does not excessively occupy the outer surface space of the cover 10, which is beneficial for standardized design during battery cell assembly. Furthermore, by placing the deformable part 40 inside the battery cell, the exposed terminals on the outside of the battery cell do not need to be additionally enlarged or lengthened, thus not occupying the external space of the cover 10. In addition, since the deformable part 40 is placed inside the battery cell and there is no need to create openings in the cover 10 for assembly, the sealing design is greatly reduced, improving safety and reliability. Moreover, since the deformable part 40 is placed inside the battery cell and the external terminals do not need to be designed to be large, the assembly method between the terminals and the cover 10 is not limited to riveting; injection molding can be used based on low-cost design goals. In addition, the groove 13 in this embodiment can serve as a stamping and deformation space on the cover 10. By using the groove 13 and the deformable part 40 to cooperate with each other, it is not only beneficial to avoid accidental short circuits, but also to avoid the battery size from increasing due to the setting of the deformable part 40.

[0058] According to one embodiment of this application, the cover plate further includes a connector located on the side of the cover 10 near the inside of the battery. The connector has a deformable member 40, and is used to connect with the first terminal 21. That is, the deformable member 40 can be indirectly connected to the first terminal 21 via the connector. In this embodiment, the connector acts as a bridge, reducing the difficulty of connecting the deformable member 40 and the first terminal 21. Furthermore, by placing the deformable member 40 on the connector, i.e., on the extended structure of the first terminal 21, the deformable member 40 is located inside the battery, making it less likely to affect the external terminal structure, thus avoiding external space occupation and interference with battery pack assembly. In other words, by placing the deformable member 40 on the connector and combining it with the groove 13 on the cover 10, this structural design does not alter the original internal space of the battery cell.

[0059] In some specific embodiments of this application, the connector includes a first connecting piece 50 and a second connecting piece 60. The first connecting piece 50 is used to connect with the first pole post 21, and the second connecting piece 60 is connected with the first connecting piece 50. A deformable member 40 is provided on the second connecting piece 60. For example, the second connecting piece 60 is a rectangular plate with a circular through hole, and the deformable member 40 is disposed in the circular through hole. Another example is that the second connecting piece 60 is located above the left end of the first connecting piece 50, and the second connecting piece 60 and the first connecting piece 50 are stamped as a single piece. The upper surface of the right end of the first connecting piece 50 is connected to the lower end of the first pole post 21. Yet another example is that the second connecting piece 60 is located to the left of the first connecting piece 50, the right end of the second connecting piece 60 is connected to the left end of the first connecting piece 50, the upper surface of the middle part of the first connecting piece 50 is connected to the lower end of the first pole post 21, and the first connecting piece 50 and the second connecting piece 60 are welded together.

[0060] In other words, the connector in this embodiment mainly consists of a first connecting piece 50 and a second connecting piece 60. When an insulating member 30 is provided between the cover 10 and the connector, the first connecting piece 50 and the second connecting piece 60 can be simultaneously located on the side of the insulating member 30 away from the cover 10. The first connecting piece 50 can be connected to the first pole post 21, for example, through a direct connection. A deformable member 40 is installed or provided on the second connecting piece 60, and the second connecting piece 60 can serve as a mounting carrier or an extension block. The second connecting piece 60 is simultaneously connected to the first connecting piece 50, and can simultaneously serve as both an indirect connection and a mounting carrier. In addition, the insulating member 30 can be located between the first connecting piece 50 and the cover 10, and can provide insulation and circuit breaking under normal operating conditions. At the same time, by using sheet-like first connecting pieces 50 and second connecting pieces 60, their own thickness can be reduced, for example, the thickness dimension in the X direction, thus reducing the occupied volume. In addition, the second connecting piece 60 can act as an extension piece, for example, by extending it in the Z-axis direction, to prevent interference between the deformable part 40 and the first pole post 21, and to facilitate the installation of the deformable part 40.

[0061] Optionally, one end of the first connecting piece 50 in the Z-axis direction is connected to the end of the first pole post 21 in the X-axis direction, and the other end of the first connecting piece 50 in the Z-axis direction is connected to one end of the second connecting piece 60 in the Z-axis direction. The deformable member 40 is disposed on the second connecting piece 60 and extends approximately along the X-axis direction. By adopting a sheet-like structure, the space occupied by the connecting piece and the deformable member 40 in the X-axis direction can be reduced. By adopting the second connecting piece 60, it is beneficial for the deformable member 40 to be deformed under force.

[0062] The following detailed description of the short circuit when the deformed part 40 of this application contacts the cover 10, with reference to specific embodiments, is provided below.

[0063] The current path under short circuit is: positive terminal post — cover 10 (aluminum sheet) — deformable part 40 — second connecting piece 60 — first connecting piece 50 — negative terminal post. Since the electrochemical resistance of the electrode assembly inside the cell is larger than the ohmic resistance of the structural parts, the current preferentially passes through the low resistance current shunt, which can shield the further electrochemical reaction of the electrode assembly 90 inside the cell and improve safety.

[0064] According to one embodiment of this application, the second connecting piece 60 is welded to the first connecting piece 50, for example, one end of the second connecting piece 60 in the Z-axis direction is welded to one end of the first connecting piece 50 in the Z-axis direction; or, the second connecting piece 60 and the first connecting piece 50 are integral parts. For example, the first electrode post 21, the first connecting piece 50, and the second connecting piece 60 are integrally formed by stamping, or the second connecting piece 60 is welded to the first connecting piece 50 to form an electrical connection path. It can be seen that the connection methods of the second connecting piece 60 and the first connecting piece 50 are diverse and can be manufactured using different processes. For example, the negative electrode post, the first connecting piece 50, and the second connecting piece 60 can be formed by stamping in one step, which can make the structure more robust; or, the negative electrode post and the first connecting piece 50 can be formed by stamping in one step, and the second connecting piece 60 and the first connecting piece 50 can be welded together, improving structural robustness. Optionally, when the first electrode post 21 is a negative electrode post, the second connecting piece 60 can be directly connected to the negative electrode tab of the electrode assembly 90 inside the battery.

[0065] Optionally, the second connecting piece 60 has a space to accommodate the welding assembly of the deformable part 40, which facilitates the welding connection between the deformable part 40 and the second connecting piece 60.

[0066] According to one embodiment of this application, the deformable member 40 includes a connecting portion 41, a flipping portion 42, and a protrusion 43. The protrusion 43 is disposed in the middle of the flipping portion 42 and extends toward the cover 10. When the internal pressure of the battery increases to a preset value, the flipping portion 42 moves toward a position closer to the cover 10, so that the protrusion 43 contacts the cover 10. That is, after the protrusion 43 of the deformable member 40 moves upward, it enters the groove 13.

[0067] In other words, the deformable part 40 includes a connecting part 41, a flipping part 42, and a protrusion 43. For example, the connecting part 41 is located in the middle of the first connecting piece 50 or the second connecting piece 60, or near the Z-axis end. The connecting part 41 connects the connecting part and the flipping part 42. For example, the second connecting piece 60 and the flipping part 42 are connected through the connecting part 41. The protrusion 43 is located in the middle of the flipping part 42 and extends toward the cover 10. For example, the height of the protrusion 43 extends approximately along the X-axis. When the internal pressure of the battery increases to a preset value, the flipping part 42 moves toward a position closer to the cover 10 so that the protrusion 43 contacts the cover 10. That is, the flipping part 42 is used to deform as the air pressure increases during battery cycling. For example, the deformable part 40 is provided on the second connecting piece 60. When the internal pressure of the cell increases, it deforms and flips upward, and the protrusion 43 contacts the cover 10 to form a current path loop, achieving short-circuit protection under overcharge.

[0068] Furthermore, when using the modified part 40 of the present application embodiment, the assembly form of the pole is not limited, and when injection molding is used, it has a cost advantage over riveting structure.

[0069] Furthermore, traditional flip-top plates are located on or outside the cover 10, which places excessively high demands on welding reliability or requires secondary sealing design. In contrast, the modified component 40 structure of this application embodiment does not change the original electrode sealing assembly structure, thus improving the overall sealing safety of the battery cell.

[0070] In this embodiment, the deformable part 40 mainly adopts a combination of a connecting part 41, a flipping part 42, and a protrusion 43. For example, the deformable part 40 is a flipping piece composed of the connecting part 41, the flipping part 42, and the protrusion 43. The connecting part 41 can connect the second connecting piece 60 and the flipping part 42. For example, the connecting part 41 is located between the second connecting piece 60 and the flipping part 42. The protrusion 43 is located in the middle of the flipping part 42. For example, the protrusion 43 is located at the center of the flipping part 42. When the internal pressure of the battery increases to a preset value, the flipping part 42 moves toward a position closer to the cover 10, and the protrusion 43 also moves toward the cover 10, so that the protrusion 43 extends out of the third through hole 33 and contacts the cover 10.

[0071] In some specific embodiments of this application, the protrusion 43 is a conical column structure extending toward the cover 10. Along the thickness direction of the cover 10, the radial dimension of the protrusion 43 gradually increases. The groove 13 is a semi-circular groove, and the radial dimension of the groove 13 at the position corresponding to the protrusion 43 decreases as the radial dimension of the protrusion 43 decreases. That is, the radial dimension of the end of the protrusion 43 near the cover 10 is smaller than the radial dimension of the connection between the protrusion 43 and the mounting portion 422. For example, if the protrusion 43 extends vertically, its upper end extends toward the cover 10 and has a small radial dimension, while its lower end connects to the mounting portion 422 and has a large radial dimension. Furthermore, the groove 13 is a semi-circular groove, and the radial dimension corresponding to different positions of the groove 13 and the protrusion 43 decreases as the height of the protrusion 43 increases.

[0072] In other words, the protrusion 43 is a conical column structure, and its height in the X-axis direction can be defined as L. A groove 13 is provided at the corresponding position on the aluminum sheet, and the radius of the groove 13 is R1. The height of the protrusion 43 is divided into L0, L1, and L2; L0 > L1 > L2, and the radius corresponding to L0 is R3; the radius corresponding to L1 is R2, and the radius corresponding to L2 is R1. The relationship between the radii satisfies R3 < R2 < R1. This allows the protrusion 43 to contact the aluminum sheet more firmly when the movable part 421 is flipped, making it less likely to melt and cause a short circuit. If the gas pressure inside the battery is at a critical value near a threshold, it can prevent incomplete short circuits caused by the protrusion 43 not contacting the cover 10 tightly.

[0073] According to one embodiment of this application, the cover plate further includes: an insulating member 30, located on the side of the cover body 10 near the inside of the battery. The insulating member 30 is provided with a first through hole 31, a second through hole 32, and a third through hole 33. The first through hole 31 corresponds to the position of the first mounting hole 11 to install a first terminal 21 that is insulated from and connected to the cover body 10. The second through hole 32 corresponds to the position of the second mounting hole 12 to install a second terminal 22 that is electrically connected to the cover body 10 and has the opposite polarity to the first terminal 21. One end of the deformable member 40 is connected to the first terminal 21, and the other end of the deformable member 40 corresponds to the position of the third through hole 33. In addition, a groove 13 is provided on the side of the cover body 10 near the insulating member 30, for example, a groove 13 is provided on the inner side of the cover body 10 in the X-axis direction. When the other end of the deformable member 40 passes through the third through hole 33 and contacts the cover body 10, the groove 13 accommodates the other end of the deformable member 40.

[0074] In other words, an insulating component 30 is provided on the side of the cover 10 near the inside of the battery, for example, the insulating component 30 is arranged approximately parallel to the cover 10. The insulating component 30 can be made of plastic sheet or the like, and the space occupied can be reduced by adopting a plate-like structure. The insulating component 30 is provided with a first through hole 31, a second through hole 32 and a third through hole 33, for example, the first through hole 31, the second through hole 32 and the third through hole 33 are spaced apart along the Z-axis, and the third through hole 33 is located between the first through hole 31 and the second through hole 32.

[0075] The first through hole 31 corresponds to the position of the first mounting hole 11, and the second through hole 32 corresponds to the position of the second mounting hole 12, for example, in the X-axis direction. That is, the inner end of the first pole post 21 can pass through the first mounting hole 11 and the first through hole 31 in sequence and then connect to the corresponding tab. Similarly, the inner end of the second pole post 22 can also pass through the second mounting hole 12 and the second through hole 32 in sequence and then connect to the corresponding tab.

[0076] Additionally, a deformable member 40 is directly or indirectly connected to the first pole post 21. At least a portion of the deformable member 40 corresponds to the position of the third through hole 33, for example, in the X-axis direction. Therefore, the insulating member 30 has a third through hole 33, which allows the deformable member 40 to contact the cover 10 after deformation. For example, at least a portion of the deformable member 40 deforms along the X-axis direction, passing through the third through hole 33 during deformation until it contacts the cover 10.

[0077] When the internal pressure of the battery is less than a preset value, the deformable part 40 is completely separated from the cover 10. As the internal pressure of the battery increases to the preset value, a portion of the deformable part 40 can extend out of the third through-hole 33 under pressure until it contacts the cover 10, thus forming a short circuit. For example, when the internal pressure of the battery increases, the deformable part 40 will deform towards the cover 10, passing through the third through-hole 33 until it contacts the cover 10. Since the cover 10 is electrically connected to the positive terminal, the entire cover 10 is positively charged. The deformable part 40 is connected to the negative terminal, therefore, the deformable part 40 is negatively charged. Therefore, when the deformed part 40 contacts the cover 10 after deformation, a positive-negative short circuit is formed, protecting the battery.

[0078] Optionally, along the direction from the cover 10 to the insulator 30, for example along the X-axis, the orthographic projection of the deformable member 40 is located inside the third through hole 33. For example, the outer contour of the deformable member 40 is circular, and the radius of the third through hole 33 is not less than the radius of the deformable member 40. In this embodiment, the difficulty of contacting the deformable member 40 with the cover 10 can be reduced.

[0079] In some specific embodiments of this application, one end of the deformable member 40 is located on the side of the insulating member 30 away from the cover 10. When the deformable member 40 is provided on the connector, the connector is located on the side of the insulating member 30 away from the cover 10, for example, the connector is located below the insulating member 30 in the X-axis direction, the first connecting piece 50 is located on the side of the insulating member 30 away from the cover 10, the first connecting piece 50 is used to connect with the first pole post 21, the second connecting piece 60 is connected to the first connecting piece 50 and is located on the same side of the insulating member 30 as the first connecting piece 50, and the deformable member 40 is provided on the second connecting piece 60.

[0080] Furthermore, a deformable member 40 is provided on the connector, which is used to connect to the first terminal 21. For example, the connector is located on the outer side of one end of the first terminal 21 near the inside of the battery, and the deformable member 40 is also provided on the connector. In this embodiment, the deformable member 40 can be provided on the connector, which can reduce the space occupied by the deformable member 40. Optionally, one end of the connector in the Z-axis direction is connected to the end of the first terminal 21 in the X-axis direction, and the deformable member 40 is provided in the middle of the connector or in the region near the other end in the Z-axis direction, which can reduce the size of the battery in the Z-axis direction.

[0081] In some specific embodiments of this application, the first electrode post 21 is the negative electrode post, the second electrode post 22 is the positive electrode post, and the cover 10, the first electrode post 21, and the deformable part 40 are made of the same material. For example, the cover 10 is made of light aluminum sheet, the shell 80 is an aluminum shell, and the first electrode post 21 is a negative electrode post made of aluminum. In this embodiment, the cover 10, the negative electrode post, and the deformable part 40 of the battery are made of the same material. For example, the negative electrode post can be made of aluminum, the first connecting piece 50 connected to the negative electrode post is also made of aluminum, and the second connecting piece 60 connected to the first connecting piece 50 and the deformable part 40 are also made of aluminum. At this time, the negative electrode post, the first connecting piece 50, the second connecting piece 60, and the flip piece are all made of the same material, which can improve the reliability of the welding connection. It should be noted that, compared with lithium batteries, lithium batteries need to use electrode posts made of copper, etc., and cannot use aluminum as the negative electrode current collector. Therefore, when the battery in this embodiment is a sodium-ion battery, the cost of the structural components can be reduced.

[0082] According to one embodiment of this application, such as Figure 13 and Figure 15 As shown, the distance between one end of the deformable member 40 and the side of the cover 10 near the inside of the battery is H1. For example, if the cover 10 and the insulating member 30 are stacked vertically, the distance between the lower end face of the area on the cover 10 where the groove 13 is not provided and the lower end face of the connecting part 41 is H1. Additionally, as... Figure 13 and Figure 15As shown, the depth of the groove 13 is H2, and H1 and H2 satisfy: 1.4mm ≤ H1 + H2 ≤ 3.5mm. In this embodiment, by limiting 1.4mm ≤ H1 + H2 ≤ 3.5mm, for example, the sum of H1 and H2 is 1.4mm, 1.5mm, 1.8mm, 2.0mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm, or 3.5mm, it not only facilitates the flexible deformation of the deformable part 40, but also facilitates the contact of the deformable part 40 with the inner wall of the groove 13 under the action of the internal air pressure of the battery. For example, in the X-axis direction, the distance between the upper surface of the second connecting piece 60 and the lower surface of the cover 10 is H1, and the maximum depth of the groove 13 is H2, where 1.4mm ≤ H1 + H2 ≤ 3.5mm. The protrusion 43 cooperates with the groove 13, which neither affects the internal space of the battery nor hinders the deformation of the deformable part 40, thus ensuring the insulation effect between the deformable part 40 and the cover 10 under normal air pressure. In this embodiment, the shape of the groove 13 corresponds to the other end of the deformable part 40, for example, to the shape of the protrusion 43. In addition, since the other end of the deformable part 40 can extend into the groove 13, when projected in the X-axis direction, the outer edge of the groove 13 encloses a first projection area, and the other end of the deformable part 40 corresponds to a second projection area, which is located inside the first projection area. In this embodiment, the shape of the groove 13 is not limited.

[0083] Optionally, the cover 10 may also be equipped with an explosion-proof valve and / or a liquid injection port, which is highly integrated.

[0084] Optionally, the upper part of the positive electrode post is further provided with a positive electrode upper plastic 71, which can be the upper part in the X-axis direction. The positive electrode upper plastic 71 and the positive electrode adapter 75 can snap the positive electrode post into the second through hole 32 of the cover 10 and the insulating member 30 to fix the positive electrode post. Similarly, the upper part of the negative electrode post is provided with a negative electrode upper plastic 72. The negative electrode upper plastic 72 and the first connecting piece 50 can snap the negative electrode post into the first through hole 31 of the cover 10 and the insulating member 30 to fix the negative electrode post. Optionally, when the negative electrode post corresponds to the first through hole 31, a groove structure 13 is provided around the first through hole 31, and the corresponding position of the negative electrode upper plastic 72 has a concave-convex structure. This structure can further strengthen the fixation between the negative electrode post and the cover 10.

[0085] In other words, the electrode body passes through the electrode hole in the cover 10, and the connecting block of the electrode is set on the side of the insulating member 30 near the electrode assembly 90. The electrode has an upper plastic layer on the end near the cover 10. The upper plastic layer and the connecting block can be used to snap the electrode into the plate-like structure formed by the insulating member 30 and the cover 10, for example, to fix the electrode in the X-axis direction. The first connecting piece 50 can serve as the connecting block for the negative electrode.

[0086] Optionally, the insulating component 30 is provided with a filter structure at the position corresponding to the injection hole, which can be used to prevent the electrode assembly 90 from being damaged by excessively fast injection speed.

[0087] Optionally, the insulating component 30 is provided with a lower protrusion structure at a position corresponding to the cover 10. The lower protrusion structure is a hollow structure used to form a gas passage between the inside of the battery and the explosion-proof valve.

[0088] According to one embodiment of this application, the first terminal 21 is a negative terminal and the second terminal 22 is a positive terminal, which can be applied to a battery.

[0089] In some specific embodiments of this application, the cover 10, the negative terminal post, and the deformable part 40 are made of the same material, which can improve the reliability of the connection.

[0090] Optionally, the cover 10 is provided with a recessed structure around the first mounting hole 11 and / or the second mounting hole 12, and the pole post has corresponding protrusions and recesses. This structure makes the connection between the pole post and the cover 10 more secure.

[0091] This application also discloses a battery, including: a housing 80, a cover plate and an electrode assembly 90, wherein the cover plate is any of the cover plates described above, and a receiving space is enclosed between the housing 80 and the cover body 10 of the cover plate, and the electrode assembly 90 is located in the receiving space.

[0092] For example, a sodium-ion single-cell battery includes a casing 80, a cover plate, and an electrode assembly 90. The casing 80 is an aluminum casing, optionally formed by stretching and having a semi-closed opening. The cover plate includes a cover body 10 and an insulating member 30. The cover body 10 can be placed over the opening of the aluminum casing to seal the battery casing 80. The electrode assembly 90 is housed within the aluminum casing. The electrode assembly 90 includes multiple cores formed by winding a positive electrode sheet, a separator, and a negative electrode sheet. The positive electrode sheet includes a positive electrode active material, which can be selected from one or more of layered oxides, polyanionic compounds, and Prussian blue compounds. The negative electrode sheet includes a negative electrode active material, which can be selected from one or more of hard carbon and soft carbon. Since layered oxide positive electrodes have a high theoretical specific capacity and an open layered structure, and hard carbon has high specific capacity and good sodium storage performance, the batteries in this embodiment have high energy density and good rate performance; therefore, hard carbon is preferred.

[0093] According to one embodiment of this application, layered oxide is used as the main positive electrode material. Layered oxide has a large gas production and slightly lower stability. When gas is continuously produced during battery cycling, it will cause changes in the gas pressure inside the battery. When the gas pressure inside the battery increases, the flipping part 42 will deform. The flipping part 42 will move towards the cover 10, and the protrusion 43 will pass through the third through hole 33 on the insulating member 30 and then contact the cover 10. Thus, a short circuit structure is formed.

[0094] Optionally, such as Figure 3 As shown, the battery also includes a positive electrode adapter 75. One side of the positive electrode adapter 75 is connected to the positive electrode connecting block 74 on the positive electrode post, and the other side is connected to the positive electrode tab of the electrode assembly 90. For example, in the X-axis direction, the upper surface of the positive electrode adapter 75 is connected to the positive electrode connecting block 74 on the positive electrode post, and the lower surface is connected to the positive electrode tab. The second connecting piece 60 is connected to the first connecting piece 50 and also to the negative electrode tab of the electrode assembly 90. This avoids occupying internal battery assembly space by using a separate connection structure. For example, one end of the second connecting piece 60 in the Z-axis direction is connected to the first connecting piece 50, and the other end of the second connecting piece 60 in the X-axis direction is connected to the negative electrode tab. In addition, the positive electrode adapter 75 is located on the side of the insulating member 30 closer to the inside of the battery, for example, located below the insulating member 30 in the X-axis direction.

[0095] Optionally, a sealing ring 73 is also provided between the positive terminal and the cover 10 for sealing. Optionally, a sealing ring 73 is also provided between the negative terminal and the cover 10 for sealing and insulation.

[0096] The cover plate of this application will be described in detail below with reference to specific embodiments and comparative examples.

[0097] In Example 1, the distance H1 between the second connecting piece 60 and the surface of the aluminum sheet is 2.7; the depth L2 of the receiving groove is 0.5; and the sum of H1 and H2 is 3.2.

[0098] In Example 2, the distance H1 between the second connecting piece 60 and the surface of the aluminum sheet is 2.7; the depth H2 of the receiving groove is 0.8; and the sum of H1 and H2 is 3.5.

[0099] In Example 3, the distance H1 between the second connecting piece 60 and the surface of the aluminum sheet is 1.3; the depth H2 of the receiving groove is 0.1; and the sum of H1 and H2 is 1.4.

[0100] Overcharge tests were performed on the batteries of the above embodiments:

[0101] At 25°C, the battery cells were charged at a constant current and constant voltage of 0.33C to the upper limit cutoff voltage of 3.85V, and then charged at a constant voltage to a current of 0.05C. The battery cells were then charged for 1 hour under the following conditions or the voltage of the battery cells reached 1.5 times the upper limit cutoff voltage. The experimental results are shown in Table 1 below.

[0102] Table 1

[0103]

[0104] Based on the above results, the distance between one end of the deformable part 40 and the side of the cover 10 near the inside of the battery is H1, and the depth of the groove 13 is H2. 1.4mm≤H1+H2≤3.5mm. The deformable part 40 can be flipped normally in time, which can protect the battery. In addition, the cover plate has a small thickness in the X-axis direction, and the assembled battery has the advantage of small size.

[0105] In summary, by providing the deformable member 40 on the first terminal post 21, short-circuit protection can be provided for the battery when the internal gas pressure increases during battery cycling, preventing phenomena such as battery thermal runaway and explosion, and improving battery safety. Moreover, the cover plate according to the embodiment of this application not only achieves the function of protecting the battery, but also prevents the battery size from becoming too large.

[0106] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A cover plate, characterized in that, include: The cover (10) has a first mounting hole (11) and a second mounting hole (12) and a groove (13) is provided on the side of the cover (10) near the inside of the battery. The first pole (21) and the second pole (22) are installed in the first mounting hole (11) and are insulated from the cover (10). The second pole (22) is installed in the second mounting hole (12) and is electrically connected to the cover (10). The polarity of the second pole (22) is opposite to that of the first pole (21). The deformable part (40) is located on the side of the cover (10) near the inside of the battery. One end of the deformable part (40) is connected to the first terminal (21). When the internal pressure of the battery is less than a preset value, the deformable part (40) is separated from the cover (10). When the internal pressure of the battery increases to the preset value, the other end of the deformable part (40) moves toward the cover (10) and contacts the cover (10) to form a short circuit. The groove (13) accommodates the other end of the deformable part (40).

2. The cover plate according to claim 1, characterized in that, Also includes: A connector is located on the side of the cover (10) near the inside of the battery, and the connector is provided with the deformable part (40). The connector is used to connect with the first pole post (21).

3. The cover plate according to claim 2, characterized in that, The connector includes: The first connecting piece (50) is used to connect with the first pole post (21); The second connecting piece (60) is connected to the first connecting piece (50), and the deformable part (40) is provided on the second connecting piece (60).

4. The cover plate according to claim 1, characterized in that, The deformable part (40) includes a connecting part (41), a flipping part (42) and a protrusion (43). The protrusion (43) is located in the middle of the flipping part (42) and extends toward the cover (10). When the internal pressure of the battery increases to a preset value, the flipping part (42) moves toward a position close to the cover (10) so that the protrusion (43) contacts the cover (10).

5. The cover plate according to claim 4, characterized in that, The protrusion (43) is a conical column structure extending toward the cover (10). Along the thickness direction of the cover (10), the radial dimension of the protrusion (43) gradually increases. The groove (13) is a semi-circular groove. The radial dimension of the groove (13) corresponding to the position of the protrusion (43) decreases as the radial dimension of the protrusion (43) decreases.

6. The cover plate according to claim 1, characterized in that, Also includes: An insulating component (30) is located on the side of the cover (10) near the inside of the battery. The insulating component (30) is provided with a first through hole (31), a second through hole (32) and a third through hole (33). The first through hole (31) corresponds to the position of the first mounting hole (11) to install the first terminal (21). The second through hole (32) corresponds to the position of the second mounting hole (12) to install the second terminal (22). One end of the deformable component (40) is connected to the first terminal (21), and the other end of the deformable component (40) corresponds to the position of the third through hole (33).

7. The cover plate according to claim 6, characterized in that, One end of the deformable member (40) is located on the side of the insulating member (30) away from the cover (10).

8. The cover plate according to claim 1, characterized in that, The first pole (21) is a negative pole, the second pole (22) is a positive pole, and the cover (10), the first pole (21) and the deformable part (40) are made of the same material.

9. The cover plate according to any one of claims 1-8, characterized in that, The distance between one end of the deformable part (40) and the side of the cover (10) near the inside of the battery is H1, and the depth of the groove is H2, 1.4mm≤H1+H2≤3.5mm.

10. A battery, characterized in that, include: The housing (80) and the cover plate, wherein the cover plate is any one of the cover plates described in claims 1-9, and a receiving space is enclosed between the housing (80) and the cover body (10) of the cover plate; Electrode assembly (90) is located in the containment space.

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